Study On The Structure And Properties Of Sample Molded By Oscillating Push-pull Molding Of Polymer Melt

Our research based on the self-made loop oscillating push-pull molding equipment andintroducted reciprocating shear dynamic force field or reciprocating oscillating shear forcefield in the process, comparatively researched and analysised the change rule and mechanismof the aggregation structure and performance of three different types polymers under differentdynamic force field.1.With selection of commonly used high crystallization type high density polyethylene(HDPE) and using self-made loop oscillating push-pull equipment for conventional extrusionmolding, loop push-pull and loop oscillating push-pull molding experiments,wecomparatively study the mechanical properties of the products under different force fields.The results showed the tensile strength, impact strength and modulus of elasticity of the looppush-pull molding products by introducing reciprocating shear dynamic force field increasedrespectively by85%,113%and48%compared with conventional extrusion molding wichbelongs to static molding.After the introduction of reciprocating oscillation shear dynamicforce field the loop oscillating push-pull molding products performance is further increasedby26%,39%and26%compared with loop push-pull molding process.By utilizing PLM,DSC,2D-WAXD and SEM microstructure characterization methods the aggregationmicrostructure of molding products was characterized, contrastly analysis the changemechanism of the performance and the aggregation structure of of high crystallinity polymerHDPE procducts under the action of the reciprocating shear dynamic force field andreciprocating oscillating shear composite dynamic force field.We found the reason ofimproving the mechanical properties of HDPE products was due to generate shish-kebeb andinterlocked shish-kebeb structure, and improved the orientation degree and crystallinity of theproducts under the action of dynamic force field.That reciprocating oscillating shearcomposite dynamic force field leaded to increase more shish-kebeb and thicken orientationlayer, reducing shish-kebeb inter-locked disorders and furtherly increase products crystallinityof is the cause of furtherly improving products mechanical properties compared withreciprocating shear dynamic force field. It is the prominent advantage of reciprocatingoscillation shear composite dynamic force field compared with single reciprocating shear dynamic shear force field that the tensile and impact strength of HDPE products weresignificantly improved by inductively generating multiply number shish-kebeb and thickenorientation layer.2.With selection of commonly used semicrystalline isotactic polypropylene (iPP) andusing self-made loop oscillating push-pull equipment for conventional extrusion molding,loop push-pull and loop oscillating push-pull molding experiments,we comparatively studythe mechanical properties of the products under different force fields. The results showed thetensile strength, impact strength and modulus of elasticity of the loop push-pull moldingproducts by introducing reciprocating shear dynamic force field increased respectively by52%,160%and87%compared with conventional extrusion molding wich belongs to staticmolding.After the introduction of reciprocating oscillation shear dynamic force field the looposcillating push-pull molding products performance is further increased by19%,79%and12%compared with loop push-pull molding process.By utilizing PLM, DSC,2D-WAXD andSEM microstructure characterization methods the aggregation microstructure of moldingproducts was characterized, contrastly analysis the change mechanism of the performance andthe aggregation structure of of high crystallinity polymer HDPE procducts under the action ofthe reciprocating shear dynamic force field and reciprocating oscillating shear compositedynamic force field.We found the reason of improving the mechanical properties of iPPproducts was due to reduce sphaerocrystal size and increase sphaerocrystal density, andimproved the orientation degree and crystallinity of the iPP products under the action ofdynamic force field.That reciprocating oscillating shear composite dynamic force field leadedto furtherly sphaerocrystal size and increase sphaerocrystal density and furtherly increaseproducts crystallinity of is the cause of furtherly improving products mechanical propertiescompared with reciprocating shear dynamic force field. It is the prominent advantage ofreciprocating oscillation shear composite dynamic force field compared with singlereciprocating shear dynamic shear force field that the mechanical property of iPP productswere significantly improved by furtherly reducing sphaerocrystal size, increasingsphaerocrystal density and the orientation of the lamella between the sphaerocrystals.3.With selection of commonly used amorphous high impact polystyrene (HIPS) and using self-made loop oscillating push-pull equipment for conventional extrusion molding,loop push-pull and loop oscillating push-pull molding experiments,we comparatively studythe mechanical properties of the products under different force fields. The results showed thetensile strength, impact strength,elasticity modulus and elongation at break of the looppush-pull molding products by introducing reciprocating shear dynamic force field increasedrespectively by56%,263%,80%and27%compared with conventional extrusion moldingwich belongs to static molding.After the introduction of reciprocating oscillation sheardynamic force field the loop oscillating push-pull molding products performance is furtherincreased respectively by8%,56%,8%and22%compared with loop push-pull moldingprocess.By utilizing SEM,SAXS and TEM microstructure characterization methods theaggregation microstructure of molding products was characterized, contrastly analysis thechange mechanism of the performance, the aggregation structure and hierarchical morphologyof amorphous high impact polystyrene (HIPS) procducts under the action of the reciprocatingshear dynamic force field and reciprocating oscillating shear composite dynamic forcefield.We found the reason of reinforcing and toughening HIPS products was due to theparallel arrangement orientation pebble-like shape PB phase under the action of dynamicforce field. Reciprocating oscillating shear composite dynamic stress are introduced to makethe products further access to improve mechanical properties than loop push-pull molding, thereason for this is that the compound dynamic force field increase PB phase deformationdegree, deformation PB phase to thicken more skin layer, and the deformation of PB phaseorientation parallel arrangement more neat. It is the prominent advantage of reciprocatingoscillation shear composite dynamic force field compared with single reciprocating sheardynamic shear force field that the impact strength of HIPS products were slightly improvedthe tensile strength and significantly improve the impact strength by forming more dramaticdeformation fibrillating orientation parallel arrangement PB phase slightly improved andsignificantly improve the impact strength.